1. Field of the Invention
The present invention relates to a method, system, and computer program product for using a migration cache to cache tracks during migration.
2. Description of the Related Art
In a hierarchical storage environment, extents of tracks may be migrated between different tiers of storage devices, such as hard disk drives, solid state storage devices, etc., depending on the characteristics of the storage devices and the frequency of access and priority of data. For instance, more frequently accessed extents and/or higher priority extents may be migrated to a faster access tier from a slower access tier, and less frequently accessed extents and/or lower priority extents may be migrated to a slower access tier. When migrating extents, all the data from the extent may be copied over from one storage device to another. During the migration process, the extent may be locked so that Input/Output (I/O) requests from hosts directed to the extent are quiesced and queued until migration has completed.
There is a need in the art for improved techniques for migrating extents of tracks between storage devices.